1. Field of the Invention
The present invention relates to a rechargeable battery, and more particularly, to an electrode assembly and a pouch type lithium rechargeable battery having the same, which can minimize the total width of a battery while maximizing a distance between electrode tabs by changing the shape of insulation members surrounding the electrode tabs positioned on the electrode assembly.
2. Description of the Related Art
Generally, a rechargeable battery refers to a battery that is capable of charging and discharging, which is different from a non-chargeable battery. The rechargeable battery is widely used in electronic apparatuses such as a cellular phone, a notebook computer, a camcorder, and the like. In particular, a lithium rechargeable battery has been increasingly used because it can have an output voltage of 3.6V that is three times higher than an output voltage of a nickel-cadmium battery or a nickel-hydrogen battery. The energy density per weight of the lithium rechargeable battery is also higher than that of a nickel-cadmium battery or a nickel-hydrogen battery.
The lithium rechargeable battery uses a lithium-based oxide as a positive electrode active material and a carbon material as a negative electrode active material. Generally, the lithium rechargeable battery is classified into a liquid electrolyte battery and a polymer electrolyte battery in accordance with the kind of an electrolyte. A lithium rechargeable battery using a liquid electrolyte is called as a lithium ion battery, and a lithium rechargeable battery using a polymer electrolyte is called as a lithium polymer battery. Furthermore, the lithium rechargeable battery can be formed in various types. Typical types of the lithium rechargeable battery include cylindrical type, rectangular type, and pouch type.
The lithium polymer battery, which has been popular in recent years, can be formed in a flexible pouch type, and thus its shape is unrestricted. Furthermore, the lithium polymer battery has an excellent stability, and is lightweight. Therefore, it has an advantage for the applications of the devices that requires slimness and light weight.
As electronic apparatuses, such as a digital camera, a cellular phone, a personal digital assistant (PDA), become smaller, a demand for small size battery has increased. Hence, the width of a battery becomes narrower, and accordingly the distance between a positive and a negative electrode tabs becomes smaller. In this case, the chance that the positive electrode tab accidentally contacts the negative electrode tab increases, making the battery short-circuit. There is also a chance that an electrode tab accidentally contacts an electrode plate of opposite polarity, which also causes a short-circuit of the battery. Therefore, in spite of the high demand for the smaller battery, there is limitations for narrowing the distance between the electrode tabs.
Accordingly, a technical solution is required to minimize the total width of a battery while maximizing a distance between electrode tabs so as to prevent a short-circuit between the electrode tabs and between the electrode tabs and electrode plates.